Remote reading compass unit



Sept 2,1952 F. G.BoucHER l-:TAL 2,609,51-3 f REMOTE READING COMPASS UNIT Filed oct. 27, 1949 2 SHEETS-SHEET 1 PAIGf-l Sept. 2, 1952 E. G. BOUCHER ET AL 2,609,513

REMOTE READING COMPASS UNIT 'Filed oct. 21, 1949 2 SHEETS- Smm 2 Y (41 en f l (42 lalzented Sept. 2, 1.952

REMOTE READING COMPASS UNIT Frank G. Bouclier and Alexander B. Hildebrandt,

Tulsa, Okla., assignors to Standard Oil Development Company, a corporation of Delaware Application October 27, 1949, Serial No. 123,892

. 7 Claims.

The present invention concerns Aa new and improved device for remotely determining orientation. More particularly the invention relates to an apparatus for determining and continuously recording at the surface of the earth the orientation" of a well-logging instrument or related device while it is in an uncased bore hole at any desired depth.

In conducting various operations in the drilling or logging of oil wells or in other locations which are normally inaccessible to the operator it is often desirable to determine the orientation of a tool or exploring device or the like in the remote location. For example, in apparatus that is used for determining the dip and strike of strata through which a hole has been bored it is obvious that the orientation of a point on the logging device With respect to magnetic north must be known in order that an accurate determination of dip and strike can be made.

It is an object of this invention to provide an improved device for determining and for continuously recording at a remote point the position of an object or instrument in a bore hole with respect to magnetic north. It is a further object of the invention to provide a devicewhich may be used in conjunction with inclination devices, proling devices and the like to aid in the logging of bore holes.

Briefly the apparatus of the present invention comprises a compass device carried on a float in a transparent oil-lled chamber and supported on a universal pivot so as to permit some degree of Ytipping of the device from the vertical, the compass device Ibeing provided with an arcuate reflecting strip so placed that it will reflect light from a light source into a light-sensitive cell, the light source and the light-sensitive cell being adapted to rotate about the transparent chamber so asto pick up in the sensitive cell a pulse that willbe indicative of the position of the compass with respect to a reference point on the apparatus.

The nature and objects of the present invention will be more fully understood from the ensuing description when considered in conjunction with the accompanying drawings in which Fig. l represents a vertical view partly in section of one embodiment of the present invention; Fig. 2 represents a top view taken along line A--A of Fig. 1, with supporting structures removed; Fig. 3 depicts a record of impulses from the apparatus of Fig. 1 during use; and Fig. 4 presents a diagram of an electrical circuit to be usedin one embodiment of the invention.

Referring now specifically to Fig. 1 the apparatus illustrated may be suitably housed within a case l which may represent a portion of a larger case containing other instruments to be used in conjunction herewith, Preferably case I and the associated parts should be constructed ofnonmagnetic material such as brass or the like in order that the operation of the compass will not be interfered with. It is understood of course that the case employed may be of any desired design and may be adapted for use with any apparatus that may be placed in an oil well. Fixed within case I is a base member 2 which supports a transparent case 3 in such a manner that an oil-tight chamber I3 is provided. Transparent case 3 may be constructed of shock resistant glass or of any suitable transparent material having a softening point above the temperature to be encountered in the well or in any other location in which the instrument is to be employed.

Attached to base 2 is a vertical support member 4 having at its upper end a universal pivot 5 on which is supported a float member 6. Suspended below iioat 6 is a compass support 8 to which are attached a pair of bar magnets 9 and I0. Attached to float member 6, and disposed in a vertical plane dened by pivot 5 and bar magnets 9 and I0 is an arcuate reflecting strip 'I which may suitably be made from a flat strip of highly reiiective non-magnetic material. Approximately one-half of strip 'I is preferably covered with a non-reflective coating.

By means of threaded connections I5 one or more expandible chambers I6 are attached to base 2 so that the interior of chamber I6 is in communication with chamber I3. Cham-ber I6-is preferably constructed with a metal bellows'so as to provide for volume changes caused by variations in the temperature of the oil that iills chamber I3.

Fixed to case I above transparent case 3 is a support bracket 20 to which is attached a bearing 2| supporting a rotatable shaft 22. To the lower end of shaft 22 is fastened a geared wheel Y23 from which is suspended'a bracket 26 which supports a light source 2l and a light-sensitive cell..

shown in Fig. 2, supporting structures being!" omitted for purpose of clarity.

aiiixed to the top of case 3 is a bracket 29kto whlch is attached a mirror 30 so positionedthat 3 it Will also reflect light from source 21 into cell 28 during some portion of a complete rotation of geared wheel 23. Shaft 25 is adapted to be driven by power source 40 which may be a conventional spring wound constant speed motor or a constant speed electric motor or the like. Shaft 25 may be suitably extended upwardly within case I to operate one or more other devices in conjunction with the apparatus of this invention. Thus, for example, shaft 25 may simultaneously operate an inclinometer device such as that disclosed and claimed in copending application Serial No. 72,515 of Alexander B. Hildebrandt, filed January 24, 1949, and the said inclinometer and the orientation device of the present invention may both be employed in a bore hole logging ap-V paratus such as that disclosed and claimed in copending application Serial No. 90,324 of Frank G. Boucher, filed April 29, 1949.

In operation, shaft 25 is driven by constant speedv powersource vlll) and in turn causes wheel amplitude than that from the latter,.thus enablllgthe two to be readily distinguished.V

Conventional means may be `usedfor supply'- inggeletricalcurrent to light source 21 and for conducting electrical impulses from light sensi-- tivef cell28 to a recording device at the earths surface. ringsandsliding contacts to transfer current from;the .rctating; portion of the deviceto the nonfrotating cable. Such means are conventionaland are therefore omitted from the draw ingginorder that the latter will not be unduly'.

complicated. The electrical pulses received at 'thefearthsA surfaceY can be recorded by conventional means as for example, by causing them tofactuate: a recording galvanometer which will: produce a trace on a moving. sheet of paper-'by means.` of an-*inking pen or on afmoving-photographingpaper or filmA by meansl of a' beam. of light. The` paper or film in the conventionaliA recordingr means. is'preferably: moved through the recorder ata uniform rate in order thatzthe.

Such means will include the usual'slipv record may bevinterpretedV more simply and ac-f.

curately.

A sample record showing the traceslrec'orded:

when usingA a device such as that depicted in Fig.

1 is; shown in Fig. 3.` On this record-trace v51 is' shownto have several kicks designated'by reference-numerals 52 and 53; Kicks-52 are those representative of pulses picked up -by cell 28 upon reflection of light from strip 1' whereas kicksl 53.: represent pulses picked up by mirror-3|).v Inasmuch as `the paper is fed through the recording instrument ata uniform speed and since light position of mirror 30. with reference to the =reff ilecting half of reflecting strip 1. Thus, ifthe distance .between successive kicks `53 on chart 50 is designated as d2 and the distance between a kick 52 and an adjacent kick 53 as di, then will equal the azimuthal relation of the reflecting half of strip 1 and mirror 30.

A Sfan alternative to providing foratpulse representative ofthe position of a point on case'l by reection from mirror 3U, such a pulse may be obtained by direct electrical contact. For example, a looped contact wire 3| may be affixed to the housing of cell 28 in such a manner as to brush against a second contact wire 32, ailixed to case I, during some portion of a complete rotation of gear 23; and` thus momentarily close an electrical circuit leading to the recorder at the earths surface. Contact wires 3| and 32 are preferably made of gold alloy or else are gold plated to ensure good electrical contact.

A suitable circuit for utilizing thecontacts3l andv 32 in the circuit employed for sensitive cell. 23 is shown in Fig. 4. Variable resistor'v 38"re`p resents the variable resistance'pre'sent'ed'by sen.; sitive cell 23Y which is constructed so'that'itsf'r'esistance is lowered Whena light'be'am is'dire'cted into it. By suitable leads 4l Vand 42variable re;- sistarice 38 is connected to conventional means. for detecting changes therein and recording-them' with a recording galvanometer as hreinbefcre. mentioned. When contact 3l engages-contact"32. resistor ldiscut in across'leads AM and'. ll'2'th us` lowering the effective resistancev through resistor, 38 and giving essentially the same'effcctitdtheg recording circuit as an increase in' the. amount; of lightn entering cell 2,8 would by ltva'wering..the;I resistance of resistor 38. Resistorvi-mayLfco/rigj- Veniently be attached to case I adjacen'tfcontactA wire 32 but, in the interests of preventing; undue.- complication of the drawing,v is not shownainI Fig. 1.

The method just .described for.- introducing-lajy reference pulse or;lubber'sline pulse into the"y recording circuit hasan advantagelinthat the: reference pulse will be sharper than thezpulse,l received by reflection of light into Ycell. 28,` so. that the two-pulsescari be readily distinguvishedo.-

The advantages of the orientation apparatus? of this invention are readily IapparentrOm-Qthe; embodiment described inrFig. 1... First-.1111,

by providing oil-filled Vchamber |'3,- motion: of.

the compass is damped yand more,reliable;read ingsare obtained. Secondly,-positioningiofmemfber''on a universal'pivot ensures .that theqcorci.l pass element will be. maintained ina*,horizcntal.` position even though theinstrumentcase-isftilted-.`

at an appreciable angle from the'ver-ticakthusaf providing for anaccurateorientation of the-fcom-fpass: Curved reflector strip v1ensures-tliatflight y will bev reiiected intcsensitive: cell 2-8z'regardless.,

of the tipping of the'instrumentcasepandfthus of bracket 26,from'thevertical.

Itis to'be'understood thatthisfinventicn isrft' be limited only bythe followingfclaimsandxiot bIyi the specific embodiments described'herein;.vvlfiichf-v may be modifiedin many particulars without,

departingv from the scopeof th'ef invention.`

What is claimed is:

l. .A device for remotely indicating orientatinr comprising an non-'magnetici case, ai fluidi-@tightl chamber disposed within x said; case; att leastv ai.

portieriv of ,saidchamber being itrarisp'arent` tL light; a.; universal pivot.v supportediwithi'r'r saidi chamber, a float memberpivotallyiattached"te1r`v said pivot; ,a compass'devicefdixedto 'saidfiat member, an arcuate reflecting strip of flat cross section attached to said float member and disposed in a vertical plane defined by said pivot and the north and south poles of said compass device, a source of light rotatably attached to said case and adapted to revolve about said compass, a light-sensitive cell rotatably attached to said case and adapted to revolve about said compass in xed relation to said light source and so positioned as to receive reflected light from said reecting strip during some portion of a complete revolution of sai-el light source and said sensitive cell about said compass, a second reflective surface xed to said case in such a position as to reilect light from said light source into said sensitive cell during some portion of a revolution of said light source and said sensitive cell about said compass, and means for revolving said light source and said sensitive cell at a uniform rate.

2. Device according to claim 1 including a wheel rotatably mounted on said case with its axis vertical and in substantial alignment with said pivot, a bracket iixed to said wheel and supporting said light source and said sensitive cell and means for rotating said Wheel at a uniform rate.

3. A device for remotely indicating orientation comprising a non-magnetic case, a fluid-tight chamber disposed within said case, at least a portion of said chamber being transparent to light, a universal pivot supported within said chamber, a float member pivotally attached to said pivot, a compass device iixed to said float member, an arcuate reflecting strip of flat cross section attached to said oat member and disposed in a vertical plane deiined by said pivot and the north and south poles of said compass device, a Wheel rotatably held by said case With its axis vertical and in substantial alignment with said pivot, means for periodically rotating said Wheel, a bracket fixed to said Wheel, a source of light and a light-sensitive cell supported by said bracket in such a manner that upon rotation of said Wheel said light-sensitive cell will receive reflected light from said reecting strip during some portion of a complete revolution of said wheel, a contact point xed to said case, and a second contact point fixed to said bracket and engageable with said rst named contact point during a portion of the rotation of said Wheel.

4. Device according to claim 3 in Which said sensitive cell has a variable electrical resistance element adapted to vary in resistance according to the intensity of light received by said cell,

said device also including a 'xed resistor, one of said contact points being connected through said xed resistor to one side of said variable resistance element and the other of said contact points being connected to the other side of said variable resistance element.

5. A device for remotely indicating orientation comprising a non-magnetic case, a universal pivot supported by said case, a compass device pivotally supported on said universal pivot, an arcuate reflecting strip attached to said compass device and disposed in a vertical plane passing through the pivot, a rotatable support held by said case, a light source held by said rotatable support in a manner adapting it to revolve about said compass, a light-sensitive cell held by said rotatable support in xed relation to said light source and so positioned as to receive reflected light from said reflecting strip during some portion of a rotation of said rotatable support, means for periodically rotating said rotatable support, and reference means mounted on said case in cooperative relation with a selected point on said rotatable support whereby a reference point on said case Will be related to a reference point on the rotatable support during the rotation of said rotatable support.

6. Device according to claim 5 ln which said reference means comprises a second reflective surface xed to said case in such a position as to reflect light from said light source into said sensitive cell during some portion of the rotation of said rotatable support.

7. Device according to claim 5 in which said n reference means comprises a contact member xed to said case, said rotatable support carrying a second contact member engageable with said iirst named contact member during some portion of a rotation of said rotatable support.

FRANK G. BOUCHER. ALEXANDER B. HILDEBRANDT.

REFERENCES CITED The following references are of record in the lle of this patent:

UNITED STATES PATENTS Number Name Date 1,746,562 Sounitza Feb. 11, 1930 2,024,793 Bauml Dec. 17, 1935 f 2,332,777 Boucher Oct. 26, 1943 2,351,081 Swift June 13, 1944 2,364,908 Miller Dec. 12, 1944 2,393,186 Potter Jan. 15, 1946 2,414,566 Thomas Jan. 21, 1947 

